Traffic signal and timer



Feb. 2, 1937. A. o. OLAFSON TRAFFIC SIGNAL Affn TIMER Filed May 27, 1931 4 Sheets-Sheet 1 gwuentoz Feb. 2, 1937. A. o. OLAFSON TRAFFIC SIGNAL AND TIMER Filed May 27, 1931 4 Sheets-Sheet 2 1937- A. o. OLAFSON TRAFFIC SIGNAL AND TIMER Filed May 27, 1931 4 Sheets-Sheet 3 umummu" $2,322.; 37 47 Feb. 2, 1937. QLA-FSQN 2,069,535

TRAFFIC SIGNAL AND TIMER Filed May 27, 1931 4 Sheets-Sheet 4 sirable.

Patented Feb. 2, 1937 UNITED STATES TRAFFIC SIGNAL AND TIMER Application May 27, 1931, Serial No. 540,223

2 Claims.

This invention relates to an automatic trafilc signal and timer, wherein the same may be operated automatically by the traffic along the respective highways.

5 This signalling device is automatic in its operation, so that the vehicles traveling along the streets or highways will operate a suitable switch device or mechanism placed in the pavement or street so that when the vehicle travels over the Y n -same, the signal will be operated through a timing mechanism which controls the operation of the signals in order that traffic may pass at intersections in a regulated manner without confusion or traffic jams or long delays, which are unde- With this mechanism, the trafiic may be regulated automatically so that busy highways may have preference over more seldomly used intersecting highways and yet the main or busy highway cannot hold up traffic indefinitely along the lesser used highway.

A feature of this automatic signalling device and timer resides in a mechanically operated timing mechanism which is provided with intermittent operating means adapted to be operated by 5 the vehicles traveling along the highways or streets or by suitable switches which may be operated by pedestrians or by time clocks of a suitable nature. The timer mechanism may also be operated by suitable switch means which is operated by street cars, railways or like carriers. While automatic vehicle operating signals, using switch mechanism in the pavement or road have been used heretofore, my signal operating mechanism and timer is of a different character having a simple and positive nature, economical to manufacture and positive in operation so as not to be afiected by the burning out of tubes or other radio operating mechanism. This is an important feature in my automatic signal operating means -10 and timer and distinguishes the same from all other types of automatic vehicle operated signals used heretofore of which I am aware.

In this timer and switch mechanism for operating the signals, I provide a means of allotting certain periods of time which are readily adjustable for the highways in difierent directions so that one highway can have a period of longer time allotted to it than the other highways at the intersection, and by the intermittent operation of the means which operates the timing periods,

each highway may be allotted a definite period of time for trafiic to travel over the same before the signal can be taken away from that highway and unless traffic comes along the opposite highway, the signal may remain to permit traffic to travel along either of the highways as long as the signal is set with the GO sign along a particular highway. All of this operating mechanism is mechanical but electrically propelled and 5 after each period allotted, the timing mechanism comes to rest until again tripped for operation.

It is also a feature to provide an automatic signalling device with the timing mechanism which permits the pedestrians to operate the sig- -10 nal if it is desired. Meansis provided so that after the signal has been operated by the pedestrian, a certain interval of signalling time must elapse before the same can be reoperated so that it is impossible to get a traific jam even though lfi the signal should be tampered with by children or those pedestrians who would not have consideration for the travel of trailic in any direction on the highways. Thus, I provide a signalling device which is automatic in regulating andfi'20 adjusting itself so as to control trafiic in a practical manner, whether operated by the vehicles of trafiic, or by individual pedestrians, to regulate the signals at the intersection of highways.

The timing mechanism is an important fea 25 ture of a signal operated automatically by the vehicles or the traffic, as well as where it is desirable to have the signal operated also by the pedestrians. While pedestrian operated signals are not as well known as other types of signals .30 which are operated by timing mechanisms or automatically by the traffic, yet they have their important functions for certain intersections and they form a practical means of permitting school children to go over busy highways pro--35.

tected by the signal when set to permit them to cross. Such pedestrian operated signals of today with which I am familiar have defects which make them seriously objectionable and I believe that I have overcome these defects in this form of my timing mechanism and signalling device, which will be more fully pointed out hereinafter in the specification. A feature of my timer resides in a simple mechanism which is adapted to operate so that operating mechanism may be placed in the pavement of the highways which permits the vehicles to automatically operate the signalling mechanism through this timer. The timer is provided with means which permits the same to be set so that different intervals of time may elapse for different highways and a longer or shorter period may be provided for various highways at the intersections and yet devices placed in the pave- 5 ment will operate the timer to change the traffic signals through the timing mechanism. Further, the timer may be operated by a single pair of switching or operating mechanisms for the same in one highway, while the other intersecting highway, which would be termed the main highway with the heaviest traffic, would under all ordinary circumstances have the free rightof-way and would not require operating switches for the timer of the signal. In this form of my timer a simpler structure with fewer parts is used. The timer operating in this manner would be operated to change the signals at the intersections only at a time when traffic would come along the lesser traveled highway, and within a certain period after the vehicle had come to the intersection the timer would cause the signal at the intersection to be changed to permit the traffic on the lesser highway to pass over the main highway. With this form of my timer, after the time allotted for the traffic to pass across on to the main highway has elapsed,

my timer automatically again sets the signal 'for travel along the main highway.

There are many advantages in this simple form of timing mechanism to automatically control vehicle traffic, as well as pedestrian trafiic,

and wherein a mechanism is provided which cannot easily get out of order and which is simple in operation, positive in timing the intervals between the changes of the traffic signals "controlled by the timer, and wherein a timing mechanism is provided which may easily be set to change'the same to operate in various ways to control the traffic at intersections. These will be more fully pointed out.

The timer mechanism for regulating the in- ;terval of time of operation of traffic signals is of the character and nature as disclosed in my Patent No. 2,026,648 granted January 7, 1936 jon application Serial No. 292,834 filed July 14,

1928, and in my application Serial No. 477,510

filed Aug. 25, 1930.

In the drawings forming a part of the speci fication:

Figure 1 illustrates diagrammatically a street intersection showing the position of the street contacts and signal.

Figure 2 illustrates a front view of my timer with the front lowered.

Figure 3 illustrates diagrammatically a side view of my timer casing showing the hinge mechanism.

Figure 4 is a sectional detail on the lines 4-4 of Figure 2.

Figure 5 is a section on the lines 5--5 of Figure 2, the timer having been removed from the casing.

Figure 6 is a front view of the timer mechanism.

Figure 7 is a side elevation view of the timer mechanism.

of, the circuit closing switch operation.

Figure 10 illustrates diagrammatically one position of the motor circuit switch in operation.

Figure 11 illustrates diagrammatically a dif- Figure 12 illustrates diagrammatically a plan view of the motor circuit operating switches.

' Figure 13 illustrates the contact switch means for operating the traffic signal.

wheels bearing on the surface of the same to control the trafiic signal It By the term timer, I mean to designate the mechanical apparatus for changing the signals, and which is electrically operated, particularly when traflic actuated or when set to operate continuously. The timer A is set into a casing In which forms a closure for the same and protects the timer mechanism against the weather. The casing I0 'is formed with side walls H, a rear wall I2 and a top 13. The front wall l4 forms the door through which access to the timer A is provided.

The front wall 14 is equipped with angle members I5 on either side thereof which overlap the side walls [0 when the wall is in closed position to form a tight closure for the casing I0. The front wall closure I4 is pivoted at I6 to a pair of links I! which in turn are pivotally connected to: links l8. The links l8 are pivoted to the side walls ll] of the casing. The door in open position is illustrated in Figure 3, a lug l9 on the inner surface of the front wall l4 bearing against the front edge of the'timer and. holding the wall M in the horizontal position illustrated in this figure. In closed position, the

wall closure 14 assumes the dotted position illustrated in Figure 3, one extremity of the wall l4 extending beneath the top l3 of the casing. A suitable stop 20 limits the movement of the links Hand 18.

To enable the operator of the timer to have access to all sides of the timer mechanism, I support the timer mechanism upon a slidable plate 22 within the casing HI. The plate 22 bears upon the upwardly extending flange 23 of the bottom 24 of the casing and is provided with bearings 25 V ings, turning upon the shaft 21. A spring catch 28 on the plate 22 is provided with a hole 29 adapted to fit a pin 30 on the plate 26 to hold the plate 26 in proper relationship to the plate 22 at all times, except when access to the rear of the timer mechanism is desired. A base plate 26 spaced from the plate 26 by spacing studs 26", provides a baseto which the timer mechanism is secured.

The timer A is operated by means of an electric motor 32 which drives a series of reduction gears within the transmission housing 33. reduction gearing operates a shaft 34 which extends frcm the housing 33. A gear 35 is slidably securedagainst turning upon the shaft 34 and is adapted to engage gear teeth or pins 36 mounted on the rear of the timing disk 31. The pins 31 are arranged in concentric circles forming :a series of concentric pin gears so that by sliding the gear The along the shaft 34, the gear 35 may engage with various of the circles of pins 36. As the gear 35 is driven at a constant speed by means of the motor 32 and the reduction gearing, and as there are necessarily a different number of pins 36 in each of the concentric circles, the disk 3'! may be driven at any one of a number of desired speeds by changing the position of the gear 35. The position of the gear 35 and the circle of teeth or pins 36 with which this gear engages, is tabulated by means of an indicator 38 on the front of the timer A, which indicator is pivoted to a plate 38 which is horizontally slidable on the shaft 41 and which engages a collar integral with the gear 35 to hold the gear in adjusted position. The indicator 38 may be set in any of the notches 39 to regulate the position of the gear 35 and to provide the desire-d speed for the disks 31in accordance with the time interval desired which is listed upon the indicator plate ll). The period of time necessary for making one rotation of the disk 3? may thus be determined by placing the indicator 38 in the proper notch 39.

In order to divide the period of time of each rotation of the disk 31, to allow various lengths of time the traffic signal E displays a certain color along a certain street, I provide a pointer 42 which may be adjusted circumferentially along the surface of the disk 31. For the purpose of simplicity, I have provided a series of letters or other indicia 43 on the surface of the disk and the end 64 of the pointer 42 may be adjusted to point to any one of the letters 43. The pointer 42 is held in adjusted position by means of a pin 45 operated by a spring handle 45 normally extending into one of thenotches 81 along the periphery of the disk 3'1. The notches l? are disposed diametrically opposite the letters 43 on the disk 3'! so that the pointer 42 may be held with the point 44 adjacent any of the letters 53. Means adjustable on this pointer 42 and means formed stationary on the disk 31 act to change the traflic signal E in a manner which will be hereinafter more clearly set forth, and because of the fact that the pointer 42 is circumferentially adjustable, the time of one revolution of the disk 37 may be divided into various proportions. For any time interval or combination of time intervals displayed upon the indicator plate 40, it is only necessary to place the indicator 38 in the notch 39 at the top of the column in which the desired combination is found, determining the time necessary for each revolution of the disk 3? and to place the pointer 42 pointing toward the letter indicated with the combination on the indicator plate id to divide the time of the revolution into the desired proportions.

My timer A operates to change the signal E at the proper intervals by operating a contact switch 49 which makes the contact, as illustrated in the wiring diagram in Figure 14 to the signal lights 50 and 5! from the electrical supply line. The contact 58 is operated between the terminal points 52 and 53 by means of a pin 54 mounted upon a slidable plate 55 within the angudarly adjustable switch supporting plate 55. The plate 55 is slidable between pins 5? on the plate 55. A spring contact arm 58 is mounted through an insulation block 59 to the upwardly extending flange 55 formed along one side of the plate 55 and integral therewith. The spring contact arm 53 is provided with a hump 62 against which the pin 55 strikes as the plate 55 is moved into the dotted position illustrated in Figure 13. The spring of the arm 58 holds the same normally in contact with the terminal 53 when the arm 58 is not contacting with the pin 54. However, when the plate 55 is moved into the dotted position illustrated in Figure 13, the pin 54 bears against the hump 62 and forces the contact arm 58 into contact with the terminal 52. The contact arm 58 is electrically connected with the terminal 63.

In order that the plate 55 may slide easily with reference to the plate 55, rollers 64 and 65 are provided secured to the plate 55 and the flange 65 respectively. The roller 65 bears against the flange and the roller bears against the plate 55 when this plate is moved longitudinally to the plate 55 causing the same to slide easily thereupon.

The plate 55 is moved longitudinally to the plate 56130 connect the arm 58 alternately with the terminal 52 and then the terminal 53. The plate 55 is moved longitudinally by means mounted upon the disk 3'! which strike pins 65 and 61 secured to the plate 55. As the disk 37 rotates, wedge-shaped flange means, which will be described in detail later in the application, engage the pin 56 and the pin 61 alternately, forcing the plate 55 from the position illustrated in Figure 13 to the dotted position shown therein and return, electrically connecting the terminal 63 alternately with the terminals 52 and 53 to successively display STOP and GO lights 50 and 5! along each street of the intersection B.

The plate 55 is pivotally supported to the shaft 68 of the disk 3? by means of an arm 69 bent upwardly from the projecting flange '50 on the plate 56 and the inturned flange l2 integral with ,v

and extending upwardly from the flange 60, as

illustrated in Figure 7 of the drawings. The flange l2 and the arm 59 merely rotate upon the shaft 58 so that the plate 55 is angularly adjustable about the periphery of the disk 3'! and is spaced slightly therefrom, as illustrated in Figure 6.

In order that the traffic signal E may be oper ated only when traffic is passing the intersection B, the contact pads C and D are set into the surface of the pavement in such a manner that a circuit through the pads C and D will be closed by the weight of an automobile passing toward the intersection B over one of these pads. The timer A is arranged to operate the signal E to permit any car passing over one of the pads C1 or D to receive a G0 signal. As contact is made in the pad D, a circuit is closed to the solenoid 1.3. The solenoid i3 drives the pin '14 upwardly against the arm '55 which is pivoted at 16. The

arm 15 is illustrated in detail in Figures 10 and 11. A metal contact arm 11 is secured to the arm i5 and moves upwardly integrally with the arm F5. The pointer 42 is provided at one end with a wedge-shaped flange 18 outwardly projecting from the plane of the disk 3?. This wedge-shaped flange 78 engages with the insulated end 19 of the contact arm H when the arm i5 is in the downward position illustrated in Figure 11, but the insulated end 19 when in the raised position of Figure 10 will not be engaged by the flange l8,

the flange 78 passing beneath the same. The

path of the flange 18 is illustrated at 80 in Figures l0 and 11 to better illustrate how the end '19 of the arm H is engaged by the wedge-shaped flange 18 as the disk 3'! rotates. Once during each:

rotation of the disk 3'5, the contact arm H is forced downwardly by a lug 81 mounted upon the surface of the disk 3?, and unless the circuit through the contact pad is completed subsequently, the end 'ifi will'be forced outwardly. When F the wedge-shaped flange engages the insulated end 19 of the contact arm 11, the circuit is broken between the arm 11 and a contact finger 82 mounted adjacent the arm 11. It may be seen in Figure 14, that the circuit from the electrical supply line to the timer motor passes through the contact arms 11 and the contact finger 82. Accordingly, when the insulated end 19 is forced outwardly by the flange 18, the timer motor 32 will cease operating. The contact-11 is held in either raised or lowered position by means of an insulated spring 83 (Figure 11) secured to the base plate 26 and bearing against the same, in both positions, providing a friction retarding any change of position of this contact.

When the signal E displays a STOP light along the street F and a car passes over the contact pad D, a circuit is closed to the solenoid 13. This raises the arm 15 and the contact arm 11. If the wedge-shaped flange 18 is holding this arm ,11 away from its contact finger 82, the operation of the solenoid 13 will raise the end 19 out of contact with this flange 18 closing the circuit between the arms 11 and the finger 82 and starting the motor 32 as shown in the wiring diagram of Fig. 15. The. wedge-shaped flange 18 will then bear against the upwardly projecting pin 66 on the plate 55 and will slide this plate 55 into the dotted position illustrated in Figure 13, thus changing the signal E to display a G signal along the street F. If, however, the disk 31 is in motion subsequent to the downward actuation by the lug 8I, pad D is passed over, causing an impulse to raise the contact arm 11, the raising of the end of the contact arm 11 will place this insulated end 19 out of the path of the flange 18 so that the circuit between the arm 11 and the finger 82 will not be broken by the flange 18, and the motor 32 will continue to rotate the disk normally. Likewise, if a car passes over one of the contact pads C on the street G as the signal E displays a STOP signal for this street,

a contact will be made to the solenoid 85 which raises an arm 86 which is integrally connected with the arm 81 similar to the arm to which a contact arm 88 is secured. The contact arm 88 is identical with the contact arm 11 and operates in the same manner. The arm 88 is provided with an insulated end 89 and normally forms contact with the finger 99. The end 89 of the arm 88 is forced downwardly by the inwardly extending lug 92 formed on the end of the arm 42 which is radially adjustable from the center of the disk 31. The circuit between the arm 88 and the finger 98 is broken by means of the wedge-shaped flange 94 formed on the periphery of the disk 31.

When the signal E displays a G0 signal along oneof the streets G or F, cars passing along this street may pass the intersection without delay as long as no car approaches at right angles. A car approaching along the street G when the GO signal is displayed along the street F, will operate the solenoid 85 to raise the contact arm 88. If the disk 31 has come to rest after previous actuations, and the flange 94 has forced the end 89 of the contact arm 88 out of engagement with y the finger 90 to break the circuit, the raising of the arm 88 will immediately make contact between the arm 88 and the finger 90, starting the motor 32. The flange 94 will then bear against the pin 65 on the plate 55 sliding the plate from the dotted position in Figure 13 to the position illustrated in full lines, thus forcing the spring arm 58' of the switch 49 into contact with the terminal 53 and causing the signal E to display a G0 signal along the street G after a short period. If the disk 31 has not had suflicient time after previous actuations to rotate to break the circuit between the arm 38and the finger 90, the arm 88 will be raised and the flange 94in its rotation upon the disk will pass beneath this end 89, thus allowing the motor 32 to continue to rotate the disk 31. If no car approaches along the street F, the disk 31 will continue to rotate, the pin 92 forcing the arm 88 downwardly into the path of the flange 94 so that when the disk rotates sufliciently, the flange 94 will bear against the end 89 of the arm 88 breaking the motor circuit and leaving the signal E displaying a G0- signal along the street G.

In the circuit illustrated in Figure 14, one of the line wires I 85 is connected to the terminal I03, to the switch element 58, to one contact of each of the pads C and D, and to the switch arm" The vehicle actuation pad and operating solenoid circuits are formed by current passing through this line wire to the pads C and D. Current flows from the pads C, when the pad switch is closed, to the solenoid 85, through thissolenoid and to the other line wire I05. Current flows from the pads D, when the switch means therein is closed, to the solenoid 13, through this solenoid, and to said other line wire I05.

The motor circuits in Figure 14 extend from said one line wire I 05, through the arm 88,

through the contact 90 to the switch "II, where the current is transmitted to the central terminal on one side of the switch, and to the motor-32. From the motor 32, the circuit extends to the other central terminal of the switch I0 I, through the switch blade and to the arm 82. From this arm, the circuit extends through the contact arm 11, which is electrically connected to said other line wire I95. 7

The signal circuit extends from said one line wire to the switch element 58. The circuit extends either through the terminal 52 to one set of lights 50, or through the other terminal 53 to the other set of lights 5|. Both sets of lights 50 and 5| are electrically connected with said other line wire.

When the switch I 8| is moved into contact with terminals I03 and I04, it may be seen that it will direct current from the line wires I05 directly to the central switch terminals connected to the motor 32, to drive the motor continuously.

In the circuit shown in Figure 15, one circuit extends from one line Wire (the left hand one in Figure 15) to the switch I8 I, both to the terminal I83 and to a terminal at the other end of the switch. Current passes through the switch blade in the switch position shown to the central switch terminal which is connected to the motor 32. Passing through the motor 32, the circuit extends to the other central switch terminal of switch iOI, through the switch blade to the contact 90. Circuit extends throughthe' arm 88 and to the other line wire I85. This said one line wire is also connected to the pads C, and a circuit is provided through these pads when the switches therein are closed (ineither pad) to the solenoid 85 which is connected to said other line wire. Said one line wire is also connected to the switch element 58, through which current flows to either terminal 52 or 53, and to eitherthe lights or the lights 5|, respectively. These lights are connected to said other line wire I05. 7

As has been stated after the timer disk has revolved sufliciently to break the motor circuit and stop the motor, a car approaching on a cross street will change the signal after a short period. For example, when cars approach along the streets F and G simultaneously, after the signal Ehasdisplayed a G signal on the street G for a period of time, the car crossing the pad D will tend to change the signal E after a short interval and this intervalmust be sufiicient to allow the car crossing a pad C simultaneously .to pass the intersection before the signal is changed. Otherwise, the car on the street G would be stopped between the pad D and the intersection B and the signal would not change back automaticaily to allow itto pass. This interval may be regulated in a simple manner as will be hereinafter set forth in detail.

The contact arms 11 and 88 are oppositely disposed on either side of the disk 31. The lug 8| is mounted on the face of the disk 31 extending outwardly from this disk at a point directly opposite the inward projecting flange 94 but somewhat closer to the center of the disk. This lug 8| which forces the arm 11 down into the path of the flange 18 is thus positioned directly above the insulated end 19 of the arm 11 when the disk 31 ceases to rotate, the circuit being broken between the arm 88 and the finger90. Therefore, as long as the disk remains in this position, the arm 19 is prevented from being elevated by the solenoid 13 and successive cars passing over the pads on the street displaying the GO signal will not elevate the arm 11. This will prevent the signal E from returning to display GO after the disk starts to rotate because of cars driving over the pads during the period the signal displayed GO and after the timer motor had stopped. Thus, cars crossing the pad D while the signal E displays GO along the street F, will not act to raise the arm 11, as this arm-is held down by the lug 8|.

The lug 92 is mounted on the end of the arm 42 and extends inwardly from the disk 31. This places the lug 92 opposite the flange 18 so that as the flange 18 acts against the insulated end 19 of the arm 11 to break the contact between the arms 11 and the finger 82, the pin 92 will be positioned directly above the arm 88 and will stay in this position as long as the disk 31 is motionless, preventing the arm.88 from being elevated. Thus, cars passing over the pad C when the signal E displays GO along the street G, will not raise the arm 88 as the pin 92 prevents such raising, The disc 31, pointer 42 and flanges 18 and 94 comprise the timer member.

I provide a means of insuring a proper interval between the time the car passing over the pads C or D on the street displaying a STOP signal while the motor of the timer is stopped, and the change of the signal E, to allow cars passing over the pads on the street displaying the GO signal to pass the intersection. If this interval is not sufiicient, cars on the street displaying the GO signal would likely become stranded between the pads and the intersection. It may be seen. that a short interval of time will elapse between the raising of one or the other of the arms 11 or 88 to start the timer motor and the time the flange 18 or 94 acts to change the spring arm 58 of the contact switch 49 to a difierent position. When the gear 35 is in engagement with the outermost row of teeth 36, the disk 31 moves slowly and the interval provided is sufficient. If the plate 56 were not circumferentially adjustable about the periphery of the disk 31, increasing the speed of the disk 31 would decrease the interval of time between the raising of the arms 11 or 88 to start themotor of the timer and the changing of the signal E, because of the faster rotation of the disk 31. Means must be provided to keep the interval between the making of the contact to start the timer motor and the changing of the signal E virtually constant. This is accomplished by means of regulating the adjustment of the plate 56 about the shaft 66. As has been pointed out the plate 56 is pivotally supported on the shaft 68 by means of the arm 69 and the flange 12. This angularly adjustable plate 56 is secured to the plate 28' by means of an arm 96. The arm 96 is provided with a bifurcated end 91 between which the pin 98 secured to the arm 69 may operate. When the plate 38 is in the position illustrated in full lines in Figure 8, the plate 56 bearing the switch 49 is comparatively near the arms 11 and 88. Accordingly, the flanges 18 or 95 need not travel far in order to change the signal E after the disk begins to rotate. However, when the plate 38' is in the position illustrated in full lines, the rotation of the disk 31 is very slow and accordingly, sufiicient time is permitted, after the beginning of the rotation of the disk to allow cars on the street displaying the GO signal between the pads and the intersection to cross the intersection before the signal changes. When the plate 38 is moved into the dotted position illustrated in Figure 8, the plate 56 is angularly adjusted by means of the arm 96 to cause the flanges 18 or 94 to travel a much greater circumferential distance between the time the disk 31 begins to rotate and the changing of the signal. It may be seen, however, that when the plate 38' is in the dotted position the disk 31 travels at a much greater speed. Therefore, the interval between the start of rotation of the disk 31 and the changing of the signal E will remain practically constant regardless of the speed of rotation of the disk 31, insuring a sufficient interval after the timer motor has started to allow cars between the pads and the intersection on the street displaying the GO signal to pass the intersection before the signal will change.

My signal timer A is suited for virtually every condition of traflic, and will operate successfully under practically every possible situation. Cars on one street may travel continuously until a car approaches in the other direction. If the cars on the first street have had their proper interval, the signal will change. If theyhave not had their proper interval, the signalwill not change until this interval is elapsed. If a car is waiting to cross the intersection, the signal will change back after a predetermined interval to allow it to pass. If no car is waiting, the signal will remain on the second street until changed by a car approaching on the first street. If cars approach rapidly or continuously on both streets, the signal will change intermittently, al lowing predetermined intervals of time on each street, which intervals may be regulated as desired.

It is sometimes beneficial to have the signal operable by pedestrians, to stop traflic to allow these pedestrians to cross the street. Contact buttons on each street Wired in parallel with the contacts in the pads of that street may be provided, as illustrated at H16 in Figure 1 of the drawings.

For intersections having a lot of traffic along one street only, it is possible to construct the timer omitting one of the solenoids, one of the contact arms, and one of the contact fingers, The timer constructed in this manner will operate to break the motor circuit only when the GO signal is in one direction, and after allowing an interval on the cross street will automatically return to the busy street. A wiring diagram of this signal timer is illustratedin Figure 15 of the drawings.

The switch ml is mounted on the rear of the timer, and controls the circuit to the timer motor. When the switch is in the position illustrated in Figures 14 and 15, the timer is controlled by the pads C and D. When, however, it is desired to operate the timer mechanically to change the signal E at regular intervals constantly, the switch handle I82 may be operated to throw the switch into the other position contacting the terminals I93 and I04. This connects the motor 32 directly to the supply line I05, so that the motor operates continuously.

In accordance with the patent statutes, I have described the principles of operation of my trafiic signal and timer and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is only illustrative of a means of carrying out my invention and that obvious changes may be made within the scope of the following claims without departing from the spirit of the invention.

Iclaim:

1. In combination with a trafiic signal unit having stop and go signals for at least two interfering trafiic lanes, a traffic actuated device for each lane, an electric motor including a shaft, a circuit for energizing said motor including a pair of switches in series, one for each lane; means for displaying a go signal to any one lane while displaying a stop signal to a second lane, said motor circuit, in the absence of traffic in said lanes having the said switch for the lane with the stop signal normally open, and the other closed; means for each lane operated by actuation of a said traffic actuated device for the corresponding lane when it has the stop signal for closing said open switch whereby said motor circuit is closed; means operated by rotation of said shaft to change the display of said signals to give a go signal to the lane of the said actuated device and stop to the other lane, and means oper ated by rotation of said shaft a predetermined time after said change of signals, to open said other switch whereby the motor circuit is opened and may be closed by an actuation of the other' of said trafiic devices on the lane now having the stop signal.

2. In combination with a trafiic signalunit having stop and go signals for at least two in terfering trafiic lanes, a trafiic actuated device for one lane, a second trafiic actuated device for a second lane; an electric motor including a. shaft, a circuit for energizing said motor includ ing a pair of switches in series, one for each lane, a disk mounted on said shaft for rotation therewith, a first and ,a second cam device for corresponding lanes of said lanes mounted on said disk in circumferentially spaced relation and projecting therefrom; a first means for operating one of said switches including a cam member movable into two positions, one in the path of one of said cam devices to be engaged therewith and the other out of it, said first means maintaining its corresponding switch closed except when said one cam member is in thesaid one position and is engaged by said cam device in which case the said one switch is opened and the motor circuit open, a second means for operating the second of saidswitches including a second cam member movable into two positions, one in the path of the second cam device to be engaged therewith and the other out of it, said second means maintaining its corresponding switch closed except when said second cam member is in said one position and is engaged by said cam device in which case the said one switch is i opened and the motor circuit open, said cam devices and cam members cooperating so that only one corresponding pair may be engaged at one time, a trafiic actuated mechanism for each lane; means for displaying a go signal to a lane whose cam device and cam member are engaged, means operated by actuation of the trafilc actuated device'for another lane to move said last mentioned cam member out of the path of the last mentioned cam device whereby the motor circuit is closed, means operated by the resulting energization of said motor to display the go signal to said other lane, and operating with cooperation of said disk and cam devices a predetermined time after the beginning of each display to bring a difl'erent cam member and cam device into engagement to open said motor circuit and to restore the moved cam member back intothe path of its corresponding cam device. 

